I like the green/brown, as it is right much more often than wrong.
I don't think there is any such classification that will always be correct. 25-30:1 C:N is not easy to express in two words, given the differences between ingredients.
So a pile of green, and a pile of brown, mix and water, turn frequently is a quick and dirty recipe, easily transmitted, that will succeed what, maybe 80% of the time? That is pretty good.
I do agree that it's best to move forward with one's compost skills from there, and leave the green/brown thing behind.
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